[3] Geiger enlisted in the Marine Corps as a private on November 2, 1907, in St. Paul, Minnesota, and was sent to Naval Station Norfolk for his initial training.

Following a series of professional examinations and the passing of a Naval Medical Board he accepted his commission as a second lieutenant on February 5, 1909.

In August 1912, he was assigned to Nicaragua, where he participated in the bombardment, assault and capture of the hills called Coyotepe and Barranca.

He commanded a squadron of the First Marine Aviation Force and was attached to the Day Wing, Northern Bombing Group.

After attending the U.S. Army War College and graduating in June 1929, he was ordered to Quantico, where he was assigned duty as commanding officer, Aircraft Squadrons, East Coast Expeditionary Force.

From June 1939 to March 1941, he was a student at the Senior and the Advanced Courses, Naval War College, Newport, Rhode Island.

His citation reads in part, "Despite almost continuous bombardment by enemy aircraft, hostile naval gunfire and shore based artillery, the combined total of Army, Navy and Marine Corps units stationed at Guadalcanal under Major General Geiger's efficiently coordinated command succeeded in shooting down 268 Japanese planes in aerial combat and inflicting damage on a number estimated to be as great ...

Redesignated III Amphibious Corps in April 1944, he led this organization in the invasion and subsequent recapture of Guam during July and August 1944, and in the assault and capture of the southern Palau Islands in September and October of the same year.

Geiger led this corps into action for the fourth time as part of the Tenth Army in the invasion and capture of Okinawa.

On June 18, 1945, Geiger assumed command of the Tenth Army following the death in combat of Lt. General Simon Bolivar Buckner Jr. for the final five days of the battle.

To this day, Geiger remains the only Marine Corps officer to have ever held command of a field army.

[21] This article incorporates public domain material from websites or documents of the United States Marine Corps.